Royal Tern
Royal Tern
Thalasseus maximus
At a Glance
Common along tropical and subtropical shores, the Royal Tern is a characteristic sight along the Gulf Coast and southern Atlantic Coast, less numerous in California. Aside from a few interior localities in Florida, it is almost never found inland except after hurricanes.
All bird guide text and rangemaps adapted from Lives of North American Birds by Kenn Kaufman© 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Gull-like Birds, Gulls and Terns
IUCN Status
Least Concern
Habitat
Coasts and Shorelines, Open Ocean, Saltwater Wetlands
Region
California, Florida, Mid Atlantic, New England, Southeast, Texas
Behavior
Direct Flight, Swooping
Population
170.000
Range & Identification
Migration & Range Maps
Present year-round in most of breeding range, scarcer northward in winter. On Atlantic Coast, some wander north of breeding range in late summer. In California, more common in winter than in summer. Some southward migration occurs, as the species reaches Ecuador and Argentina in winter.
Description
18-21" (46-53 cm). C A bit slimmer than Caspian Tern, with wispy crest, fairly thick carrot orange bill. Underside of wingtips much paler. Forehead is white most of year (becomes black for part of breeding season). On Pacific Coast, see Elegant Tern.
Size
About the size of a Crow, About the size of a Mallard or Herring Gull
Color
Black, Gray, Orange, White
Wing Shape
Long, Narrow, Pointed, Tapered
Tail Shape
Forked, Long, Notched, Pointed
Songs and Calls
Harsh kee-rare, like Caspian Tern but higher pitched.
Call Pattern
Falling, Flat
Call Type
Rattle, Raucous
Habitat
Coasts, sandy beaches, salt bays. Favors warm coastal waters, especially those that are shallow and somewhat protected, as in bays, lagoons, estuaries. Also found well offshore at times, and travels freely between islands in the Caribbean. Usually nests on low-lying sandy islands.
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Behavior
Eggs
One, rarely two. Whitish to brown, blotched with reddish-brown. Incubation is by both sexes, 28-35 days, usually 30-31.
Young
Within 2-3 days after hatching, young leaves nest and joins others in group called a "creche." Both parents bring food; parents and offspring are able to recognize each other by voice, so that adults feed only their own young. Age at first flight about 4-5 weeks. Young remain with parents for up to 8 months or more, migrating south with them.
Feeding Behavior
Forages mostly by hovering over water and plunging to catch prey just below surface. Sometimes flies low, skimming water with bill; occasionally catches flying fish in the air, or dips to water's surface to pick up floating refuse. May steal food from other birds. Sometimes feeds at night.
Diet
Fish, crustaceans. Feeds mostly on small fish (up to 4" long, sometimes up to 7") and crustaceans, especially crabs. Eats wide variety of small fish, also shrimp, squid. Soft-shelled blue crabs are major items in diet on Atlantic Coast.
Nesting
Usually first breeds at age of 4 years. Nests in colonies. Courtship involves high spiraling flights by two or more birds. On ground, male presents food to female; both birds bow, strut in circles. Nest site is on ground (usually sandy) in the open. Nest (probably built by both sexes) is a shallow depression, with or without sparse lining of debris.
Climate Vulnerability
Conservation Status
Populations declined seriously in late 1800s - early 1900s when eggs were harvested from many colonies for food; made substantial comeback during 20th century. Still vulnerable to loss of nesting sites. Has declined in California since 1950, coinciding with decline in population of Pacific sardine there.
Climate Threats Facing the Royal Tern
Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.